Recoil-check for ordnance.



L M FULLER M0911. CHECK PoR ORDNANGE.- APP'LIQATIOK FILED FEB. 6, 1908. 913,488, APatented Feb. 23, 1909.

c y 6 SHEETS-SHEET 2. y 113995.

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L. M. FULLER.

RECOIL CHT-SGK FOB. 'ORDNANCEl i i APPLIGATION FILED 1mm, 190s. -9 l 3,48

L. M. FULLER, REOOIL CHECK FOR ORDNANGE. APPLICATION FILED FEB. 6,-190B.

Patented Feb. 23, 1909. 6 SHEETS-SHEET 4,.

| IIIII IIIIIL L. M. FULLER. RBCOIL CHECK FOB. ORDNANCB.

APPLICATION FILED FEB. 6, 1908.

Patented Feb. 23, 1909.

6 SHEETS-SHEET 5.

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REGOIL CHECK FOR DBDNANOB. APPLIOTION FILED PBB.6,1908.

91 3,488. f Patented Feb. 23, 1909.

6 SHEETS-SHEET 6.

, UNITED srirras rnrnivr OFFICE.

'LAWSON M. FULLER, oF THEUNITED sTATEs'ARMY, assIexoIa onora-FIFTH To wILLARnffL.

vnLInoF MOLINE, ILLINOIS. j Y. c flincoln-CHECK Fon ORDNANCE.

Appnctin sied February s, 190s. serial 119,414,618.

Specification of Letters Patent.`

.Patented Feb. 23, 1909.

To all whom it may concern.:

Be it knowh that L LAWSON M. FULLER,

major U. S. Army, and a citizen of the United States, residing at 'ashington, in

e District of Columbia., 'have invented certain new and useful -Improvements in Recoil-Checks for Ordnance, and do hereby. declarethe following to be a full, clear, and

exact description of the invention, such as will enable others skilled .in the art to which it appertains to make and use the same.

My invention relates to recoil'checks for ordnance, and the object of my invention 'is' to produce a check, whichshall be certain .15in action, simple toconstruct and which shall prodnce a substantially uniformly de-` creasing -pressure in the recoil cylinder throughout maximum recoils corresponding to 4low angles of elevation or depression, and, '2"0' also, a'constant pressure throughout shortened recoilscorresponding to higher angles of elevation. g To these ends my invention consists of a piston in a recoil cylinder having a by ass controlled by-a valve, with means by w 'ch' the-'total throttling area of the ports of the valve, ateach instant of`recoil, produces a uniformly decreasing or a uniform pressure as desired, in said cylinder at -each instant `of recoil, althouglthe lengths of the various ree'ils may v ary.

r y invention cylinder,- by Vpass and/flve, combined with means for ad3usting the latter 'automatically as the elevation of the gun is changed, and

in such a manner as to permit a. recoil exert'- ing a constant decreasing or a constant pressure in the cylinder ofa length suitable for any desired elevation. i 40 My 'nvention further consists in the novel method of obtaining the desired changing area. of the throttlin'g ports, and in the combination of parts and details vofconstruction ,4:5 `larly pointed' out in, the claims.

` My invention is applicable to any form of gun in which it is desired to limit or control the recoil, but for convenience'in description more fully hereinafter disclosed and particu- I will disclose it in connection with two'iield 5o 'howitzer mounts ofv the type now `usedin the U. S. Army. 3

Referring to the accompanying vdrawirngjs forming apart of this s ecliication, in which like numerals refer Jto 'ke parts in all the 'vviewsiz-Figure '1, 'is a longitudinal sectional view throughthe recoil cylinder and gun. Fig. 2 a transverse sectional view on the line` 2-2 'of Fig. 1. Fig. 3,islan enlargedlongitudinal sectional viewof therecoil cylinder and valve showing certain details ofconstruction. Fig. 4, represents' a developfnient, of the cylindrical valve. Fig.vv 5is a sec. tional view taken on the line 5--5 of Fig. 4, through the extreme. rear end of the valve. Fig. 6, represents a detail in perspectiveof a. portion ofthe iston. Fig. 7, is a side elevational view of tiie valve operating mechanism. Fig. 8, is a plan view of the-same.v Fig. 9, is a longitudinal sectional view similar 'to Fig-1 showing a modifiedform of valve. Fig. 9a, a detail of the trian ular port used in connection with 'this modified form of valve. Fig. 10, is a transverse sectional view similarl to Fi 2, of a gun equipped with my modified va ve. Fig. 11, is a development of the 75 cylindrical modiiied valve. Fig. 1 2, is ascetional view ofthe modified cylindrical valve taken along the lines 12---12 shown in Fig. 1 1 Fig. 13, is an end .elevational view o the modified valve. Fig.L 14, is a diagram of 80 curves corresponding to different recoils, which represent by their ordinates the velocities ofy retarded recoils of recoiling parts as a function of space, 'ann whose. ordinates are therefore directlypronortionalto the effective throttling area of the valve ports at Aeach instant of recoil. Figs. 15 and 16, lshow' curves Whose abscissze represent the times and whose ordinatesrep/resent the velocities ofthe recoiling parts'when unconstrained, 90 and Fig.' 1 7', represents the curve when the parts recoil agalnst a uniform resistance.A

1, represents the trail; 2',- the wheels '3, l the barrel; 4, the trunnions and 5, the recoil cylinder of an ordinary U. S. Army iield hovv'- 95 itzerand carriage. The recoil cylinder 5,' is provided with a b jpass, controlled by a rotating cylindrica valve 7, sliding over the g .piston `12, and, also with a cylindricalron other return passage 8. The rearendof thel -1 0() cylinder is closedby thescrew threaded plug 9,' through which asses the rod' 1.0, rigid with` the cylinder, as s own; and thefrontendoff said cylinder is closed by the plugfll, provided4 with a suitable stuffing box, through 105 which passes the liston rod 12,'v as shown. The front end 0f t 'e' piston rod v12.', is suitably providedwith' the gear wheel 1 3, which j meshes with the gear 14, carriedbythe'rod 5,at its front end. To the rear end of the elevated or depressed,lthe inion 19, will be' rotated by the rack20, lan cause the piston rod 12, to revolve by means of the .power transmitted through .the gears above enu-I nierated. The rear end ofthe piston rod 12 is liollowed vout to receive the rod 10,. as shown,when the gun returns to battery; and

it, also, carries the piston 22;.provided with.l

Lonel or more cut away places23, into which .20 fit one or more. longitudinal ribs 24, on the valve 7.. These .ribs 24, extendtlie entire length of the Valve,- and serve as guidel ribs for the-same. v v

The valve?, is' provided with a series of rows of perforations 2'5 consisting of a main orcontinuous row, ,and a plurality of auxiliary'rows and'each row of different length corres onds to a different recoil and each eX tendslv ongitudinally along the cylinder. The

3 0 number of these' rows is one in excess of the. number of theoretically correct recoils for which the valve 1s designed. That is to say,

Aeleven rows are 'shown inthe drawin s, andl they'correspond to -ten different and t eoret- 3 5 ically correctrecoils, seven of which are'of different lengths. :The -perforations 25, in any tone row, includinglthosein the associated auxiliary'rows are so chosen and so arranged, that at any instant of recoil their 40 total effective, or throttling area, is lthe call culated varea fora uniform, or' avuniformly decreasin pressiireonthe iston, as'maybe desired.a below. That is to say,it is we l5-vy the hydraulic vpressure in a' recoil c linderde pends upon the velocity of the cy der relative to the; piston and the total area of the orifices through lWhichthe contained liquid is forced; .e1-And inv order to minimizeand '50 equalize the strains on the carriage, or

mount, fit,is necessary tomake'the pull on --the'p'iston rod and consequently the pressure within'the cylinder, a .constant or a constantly diminishing pressurev at each instant of recoil.

In certaintypes' of carriages on which 3 rapid fire` guns are mounted, thecenter of gravity of the. system shifts duri recoil, and in suchl cases in 'order that stabi ty may be insured, it is necessaryat low an les of elevation, to provide .for 'a constant y dee creasing pressure and consequently a con'-` stant'ly decreasing pull'onthe iston rod. vTo accomplish these most; dcsira le results, the

c5 total effective or throttling area of the ori..

aswill more fuy aplpar herein' Y own that iices through which .the fluid coniined in the cylinder is forced, must constantly increase up to the time when the powder gases cease to act `upon the projectile; and the total throttling area of these orii'ices niust suitably 70 decrease after that jtiine, until it becomes vzero at the end of the recoil. T he dimensions of these total throttling or effective areas at each instant of lrecoil may be readily computed from well known laws, vbut I prefer to obtainthem from a curve of retarded velocities whichis of the general forni of the curves 6069, shown in Fig. 14. These curves are obtained as follows z-lt is well known that in the case of a gun recoiling freely and there# fore unconstrained, that the velocity of the ,-recoiling parts increases until the powder gases cease to act on the projectile, or until a brief interval after the projectile leaves the bore, and that a curve e, whose ordinates represent the velocitiesaiid whose abccissa the corresponding times,`.would be of. the general form shown in' Fig. `15. In other words, al curve e, whose ordinates represent the velocities of recoil at .each instant, and whose ahscissae represent time, would become a straight line such as a, Fig. 16, parallel to the axis of the abscissae after the maximum lvelocity has been attained were it not4 for friction and other opposing agencies, which 'cause the 95 same to gradually slope off as a straight line, until it lreaches zero. But'referring again to Fig. 15, since a velocity multiplied by a time represents a distance, the total area under the curve represents the distance the parts would recoil While being accelerated by the owder gases were there no opposing forces.

ut ifo' posing forces exist such as fric-tion springs, iydraulic brakes etc., they may be so chosen as to uniformly retard the velocity of the'recoiling partsg'and in suc-h case the curve e, a, in Fig. 16, will assume the forni of curve 1^, s, in Fig. 17. In like manner the total area under the curver, s, in Fig. 17, y may be made to re )resent the distance the v119 parts would recoil uring the time they are accelerated by the powder gases and retarded 'by the particular opposing forces which brought them to rest, provided we choose l y said area of particular dimensions, In other words, the curve e, a., may he made to furnish `a series of curves r, s, whose areas will correas Will-now be explained.v y Going backto Fig. 15, in order to' lix the 120 idea, suppose the total area under the curve f c,'t, in a given experiment is found to be` 11 square inches and that the recoil corres onding to this area is found to be four inc ies in 1 length, while We desire in practice a recoil of 4:4 inches. We would know at once that this areacorresponded toa recoil eleven times spond to a series of recoils of different lengths too small, and that we inust therefore get a curve r, s, having an area of 121 square inches it it is 'to correspond to a recoil of 44 inches.I 130 i., u, e, m.

In order to get the desired'zcurve 1", 8, We would lay 0H in Fig. 16 the curve e, i, shown' in Fig.y 15, and draw the ordinate i, m, so that the area t, i, m, represents 11 square inches, and the abscissa t., m, represents 4 inches of recoil. 'W e know the parts Would recoil 'forever, expending no energy if they4 were not restrained by o posing foices, andthat this curve t, e, i, 1g. 16,- Would become the straight line t, a., under such circumstances, all as above stated. Now let us suppose the parts do so recoil Without expending energy, such an unknown distance as will make the area under curve Ir, s, 121 square inches corresponding to a recoil of 44'inches, and let this distance be i, u. The total area under the curve t, e, i, u., Will 'now be the original 11' square inches plus the area of the rectangle Draw the line t, u.- Then the area of the 'triangle t, u, e, Willbe s1- u, e, X (tm. -l mv) or l; t, m (me 4)'. If we now sub# trac-t this a-'rea from the total-area under thecurve t, t, u, above, kWe iind the area under said curve and above said line t, u, to be 11 im X ,fu. t'mww 4). IfWe'substitute for i, u, its value m, v, and utthe resulting area equal tol thedesire recoil 44 incheswe get f f l 11-i-tntXmv-im(mv+4)=44.

In this equation mis known since it, like t, m, maybe determined from experiments, and the equation therefore containsonly'the one unknown quantity m, rv, Whichcan be immediately found, and which With t, m, gives the length of the abscissa of the partie-p` ular curve 1', s, We are seeking.

We have now obtained anqrea above e, line t, u, bounded by the curve irri, 'uTtore/present a recoil of 44 inches,l and it onlv re-` mains to lay it off on the axis of X." Toldo this, suitable yordinates as illustrated at i, m,

` j, h, etc., Fig. 16, are drawn, and the distances on each ordinate, such as jfk, between the' curve t, z, u, andthe hnei, u, are measured 'from the axisfofX'ii each of said ordinates in Fig. 16. One of these measurements is represented at h, ZY=` y', k, and the resulting curve t, 1 u. cornes onding to the poi-nts thus determined, repro; uces the curve t, i, u, with the` axisA of X as the abscissa. This curve t, l, 0;, is identical With the curve r, s, in Fig. 17, and has the area required.L

Having obtained a vcurve ofthe required area," and of the'fo'rni of cur/ve '73,' 8,'for a' lrecoil of 44'inches, it is next/necessary to obtain a curve Whose ordinates represent-velocities as before and Whose abscissae represent distances instead of time.' .To do this,'a distancef, g, ljg; 14, correspondingto .44 inchesis' `laid ofi' as an abscissa,-and then" the 'ordinates repre'- l senting the velocity in feet perf-'second for each inch of recoil are laid ofi". This is readily done byb'eginnin'g once-1rd of thejcurve such as r4, s, having thereqiured area,"and` after laying oft' a unit-of area -then measuring the ordinate m, n, on said curve that boundsk this unit. of area.

abscissa of the new curve to be obtained.l

Next segregatevanother unit of area in ther curve rsuch as 13's, having the 1 21 square Then erect this ordin'ate yat the end of the first inch laid off along the* inches of area, likewise measure its bounding i ordinate' o, p, and erect it at fthe end of the second inch of the abscissa and 'so on until the Whole 121 units of area have been so treated. Then by drawing a curve throught the upper extremities of all thelordinatesn... m, n, o, p, etc., so obtained, the c-urvekGO, in

T hev ordinates of this curve.

60, willl represent the velocities for each unit.4 Y. of length of recoil, and will therefore be .pro-- portional to the t'lirottling areasffor tliecor-f i res onding units.

, ince the pressures jan the piston, and

fore the recoil veloclties in a recoil cylinder, A`` having a by pass, depeifd upon 'the throttlingvi" area ofthe exit orifice, it is clear that if theA total throttling area can be made to increase,

and to diminish as fast as the recoil velocities increase and diminish, then the pressure inthe cylinder Wonldbe constant. In other Words, 1f after having obtained curve-6U, inthe manner above disclosed, or by .calculation, We now colfstrurt a valve such as 7, and provide it with perforations 2,5 1 and qyiiices 31, of such a size, and sgspaced apart that n the total area of alltlieperforations orifices that are effective in thrttlingthe fluid, or retarding the/'recoil incre ses and diminishes y -ioo at each inst-ant of recoil as .fast as the ordinates of/said curveincrease and diminish, i.

stant throughout the recoil.

The drawings show eleven rows of perfora- ...then/the pressure in the cylinder .will be con-l c y 1105" tions 25 each having two short or auxiliary i. rows and eleven openings 31, the total areas i of Which are disposed insuch'a manner that if We assign a particular set of perforations vand a particular 'opening to a particular re-4 coil, the row 28 together with its auxiliaryr roars andv its corresponding o ening Slffon exam le, and if. We start at t right -handff e b end o thisrow, the total area o a v tling perforations infront ofthe piston as vte llqthe throt LEU-5 Vgoto the left-fat first increasesup tothe point.

d, which corresponds to the time the powder* gases cease to act, and then it continually.y

decreases, as is apparent from thedistfribu`` tion of the perforations. This is becauset pistonin its extreme position, asshovpn ,foi-[fiv examplek in Fig. 3, blocks, or cuts ofi, nearly all i the throttling` area of opening 31;- and lwhenA 'f the recoil begins,.although this openingSl. is,y rapidly'uncovered, some of the perforations 26 in the long' row 28, and in its tvifo'assofl ciatedshort rows, are at the same I blocked. There'sultof this action is .to rac-A ticall ,y prevent'all fluid, except'an exceedinglvi-v7` i smal quantity from flowing in behind'the 'pistont thenrstinstant ofrecoil, -bi1t to] permita 'ra idlv increasing uantgit to flow through thepopeshing 31, and (iihrougtirthe per forations 26|of row 28, and theperforationslv ofthe associated short rows, as the recoil proceeds.; Duringthis early period of recoil,jbefore the piston 'reaches thepoint d, it will be ebserved that the throttling'. areas behind'v the' piston wholly determine the pressure,-l

'maintain it constant in the cylinderg ,'fbr'hileafter the piston leavesv the point d, andA "the opening 31, and some of the perforations' 2 6 have been uncovered, the throttling areas Y the piston are ineffective, 'while those ="1.5. in front are the only ones effective -in causin' the pressure in the cylinder toibe maintained constant. lThe proper distribution 'of'throt-- tlingareas to cause thepressure inA the cylin-v fderto -be maintained constant may be ob tained from curve 60, by providing anoriiice "at each point along the Valve which will be v proportional in area to the-decreasein the valueof the ordinate of the curve corresponda .ingto that point, so the orifice will bear such a relation to this. decrease as will produce the vpressure desired. In other words, these holes are so arranged' that on recoil the piston passes the same, and thereby cuts them out s as effective throttling areas, while therecoill velities diminish; and puts them, las wellf asthe ports 31 or 31", into act-ion asleective throttling areas, as fast as the recoil velocities increase. A suitable formula may also. Y `be employed to, ascertain the spatial re ationV 35 and size ofthe 'perforations' Itwill be ob served that this throttling area.changes very'- abru tlyy at the beginning of l'thisvrow, as '-it shou d,vowing to the individual erforations being so closely grouped .-toget er; at that oint.' In fact, each row of perforationsZ, as associated 'with it two shorter or broken rows, such as' 29 and 30 `as above stated,l thereby constituting a vtriple row and thereby causin the piston'to uncover first 'a large area whic quickly converges like the port 31, in Fig..9, and consequentl causes 'the' pressure to be constant at thc eginning of'.- the recoil. The eii'ect of this co bination is such that whether the elevation is' just right for a long and two short rows to be in exact .register at the beginning with the by pass or not, valmost perfect results are nevertheless obtained.' as has been shown .in practive. The reason for this is, the pressure, when a 554 triple 'row not in 'exact register, is'never greater than that for the shorter triple row,

noris the recoil longer than for the longerv row, as will more fully appear hereinafter." By suitable calculations and experiments, l; have succeeded in so arranging these perforations :as shown that their total throttling areas at each instant correspond so closely to the theoretical calculated areas for corre-A sponding instants, that an indicator diagram, 65 taken from a carriage in actual use, shows a elevationlperfect rectangle vfor the highangles of eleva? tion, 7andl a trapezoid offthe desired vform for the; lower.' angles, and therefore4 that the i' said' cylinder pressures are constant" 'orcons'tantlf z fdecreasing as desired at leach instant ofreco' Returning norw to the 'value 7, controlling".

'- the by 'ass.6, ndcontaining a plurality rows o perforations 215,'"Aone triple row for each theoretically correct recoil, 1t 'is' evident l thatsoflongas aparticular row-is register with the bypass, as showninliig'. 2.,' that the pressure in .the cylinderwill .be constant or constantly decreasing 'as desired. It is however very desirable and often necessary to shorten the recoil as thegun is elevated,for reasons well known'tothose, skilled 4 in this art.. To'accomplishthis vp urpose`,'l provide row. of perforations' for. each. 4 recoil, as above stated, land so groupand distribute the perforations in each row that'their throttling areasy will-at each instant. 4correspond the ordinates of ,the

lcur've of [velocities correspondingv to'` the sur recoil inquestion.- .F ig..4,-I have shown eleven triple rows for'sevenrecoils of differ-' avian-(12s, naar. @consomme 1mg-th, whilethe remaining.' triple rowsrare for shortened recoils correspondingto -higher angles of. 'lhesf'zifirst` three vrows intendedforpointblank r-ing, and for a slight elevaftion anda-slight depression of the. gun, show' their perforationsso sized and spaced as to cause f'ai slightly uniformly decreasing pres- :sure inthe cylinder before and afterthe! lprojectile. leaves the in. order to bringt at row of perforations iin. the' valve,` register with the. bypass, .which corresponds to 4a articular elevation and .a 'p articular length o? recoil, -i'tfis merely necessary to operate the elevating. mechanism, offthe gun v'when `the 'piston' will berevolved by means of the piston rodandthe ygears connected therewith, above described, ...and the valve will lbey revolvedthrough itsguide ribs until the proper row comesinto register. The construction. is such that Athe gears.' 16', `17 and'lQserVe toso multiply the movementsin'l elevation that the valve 7,

`may revolve. throughl about v35() degrees of arc, vand ,therefore the wear, or vlost motion,

l common-ly'met withl in elevating ears has no i A'appreciable v-efect on the-lengt "of, recoil.

Moreover, the recoil control'l is operated when the system'is at rest," and not subjectedV to thepressures-or strainsdue to firing, which is' distinct ladvantage. addition to this,

thecontiguous rows are so spaced a art, that as one set of p eforations begins to e moved outvor"register'withthe, bypass 6, the' other set ofperforations .begins 'to come'int'o register, sogthat the Aby pass is'alway's covered by a full continuous.' row of perforations-and its auxiliary rows; thus making it theoretic-I 'ally correct, or itis coveredbya part of a full 139 clases.

row and a partof the nent full ro'wivith all the auxiliar'yrows .or it is covered by a full continuous row andpart of each of the auxiliary rows 'on either side of it.

forations; yet, the recoil will be still controlled and 'the pressure regulated, although not quite so accurately as before. That is to say, one row of perforations have been designed for an elevation of 35 degrees, and another for an elevation of 3() degrees, and

the gun is fired at an elevation of 32 fdegrees,

the valveWill-so controlthe pressure as to make a compromise regulation-between re.-A

coils belo'nginggto 30 degrees and 35 degrees respectively. in fact, from actual firings, lthe vindicator cards taken on the carriage when the gun was so elevated as to give a compromise regulation of recoil, were barely distinguishable from the others, taken under similar conditions. when the gun Was so elevatedas to bring the proper row oflperforati'ons into action.A As, the gun comes back to'battery, -therod 10, and hollow piston rod actas a dash ot, in the mannerY Weli known, andthe or' ces 3l, serve as a ready escape for the iluid caught in the end of the cylinder. p

lnthe modication shown in Figs. 9 to 13, the piston moves and the stationary cylinder .5,-is provided with a perforated by pass 35, controlled by a perforated rotatable valve 36, ina separate cylinder 37, provided with a stuffing box through Which the valve 'stein 38, o erates. -v On the stem 38, is the gear 39, whic meshes with the gear 40, on the shaft 41, (see Fig. 10) which in turn meshes with the gear 14, operated by the movements of the cradle, as above described. Fig. 11,

shows a develo ment of the valve 36, thev. orifices 42, of w ich are oblong and substantially rectangular, instead of circular as in the case of valve 7. The arrangementof thesje orices 42, is also in independent rows,

there being one more row than the number of theoretically calculated recoils, and the combined throttling area, at any instant of recoil, in any one row is likewise proportional to the ordinate ofthe curve representing velocities of retarded recoil as a function orv space, for that instant of that particular ,recoil, as in the case oli-valve 7.

two devices are'almost the same in construction and operation, exce t for the differ`- ences above noted, and or the elongated Infact, the

It re-` sults directly from this construction, that leven if the gun is not laid to an elevationV corresponding to a particular roviT of per.

35 and 45, in the recoil cylinder.-l Another difference is that as the piston is drawn to the rear, it uncovers the V sha ed port 31, shown in plan in Fig.' 9a, and) in section in Fig; 9. 4This port gives the constantly in- -creasing opening desired, but is the saine for all lengths of recoil while in my preferredv vforni the corresponding openings may be made almost theoreticalhT correct for each calculated length of recoil.

The operation of my recoil check will, be

clear from the foregoing, but it may be summailized for the preferred form as follows :-'--r Upon''ring, the gun and cylinder recoil in the manner well known;y andthe iston reV-I maining `stationary causes the uid contained 'inf the recoil cylinder to be forced from the one side ofthe piston head through the by pass and the orifices ofthe controlling valve, around to the other side 4of the piston. The vthrottling orifices are so arranged, and

their aggregate area in iront of the piston at each instantf recoil is such, that notWithstanding the varying energy possessed by the gun and its recoiling parts at each instant,

the pressures in the cylinderwill remain substantially constant or uniformly decreasing throughout the' entire recoil neriod as de- Si-.1rd- Afr the en has nis ditslrecol; avng beenA compressed' the springs p 50 y thereby, cause t e gun to be returned to bat'- tery. 'A reverse action takes tionof thesame, the throttling rod l0,l acts like'theplunger of a, dash ypot to cushion the final movement.. When it is desired to shorten' any recoil,'it is only necessary to rotate the valve to bring into action that roW of orifices which correspond to the desired recoil, and the above o erations. will ensuewithl a less recoil trave of the gun. When firing at an elevation, the valve is automaticlace., during this counter recoil, and tornar 'the comple-y ally adjusted as the gun is'el'evated or de pressed, and a recoil'of a suitable length .at all times assured.

It will be observed that it isjnecessary,

order to' attainthe above substantially theoretically correct results, to firstobtain practically' theoretically correct ycurves ofy velocities of retarded recoils, each ofsucli curves being of the samegen'eral forni, kas shown vin Fig. 14, but differing for each 'characteristically diiierent recoils, and differing for each piece of ordnancei.` lt is then'necesl.

sary to so select, vspace and arrange the per,-

forations25, or, orifices 42, in the valve, that y, their combined tlirottling area for veach inl stant of recoil, and for each recoil differing in kind, will be proportional to lthe ordinate ofthe curve for that instant corresponding toytlie-recdil'in question, It is evident that the special arrangement and the area yof these individual oienings may be determined in any'suita le manner, but lf'preferl to employ a ysuitable .formula to attain these ends.

It is also evident that thefdetails of construction, arrangement of parts, and method of obtaining my velocity curves,

may be widely varied without de iarting decreasing the number oftheoretically per- 'feet recoils.

Other changes ,coming Within the spirit of my invention will likewise readily suggestthemselves to ordnance engineers and others skilled in this art.

Having now described my invention what ,I claim is l.' rlhe combination of a recoil mechanism provided with recoil checking means, and

means to control such checking means at- .each instant of recoil in proportion to the retarded velocity for the .instant in question, substantially as described.

2.y In a gun mount, thev combination of a recoil cylinder and piston provided with a by pass, with means adapted to change said by pass in proportion to the changes in theretarded velocities ofthe recoiling parts at each instant of recoil, and thereby cause the pres-.

sure in the cylinder to remain substantially constant throughout the recoil, substantially as described.

3. In a gun mount thel combination of a V piston and recoil cylinder containing a fluid and provided with a by pass, and automatic means ada ted as the gun recoils to vary the exit of sai fiuid through saidby ass in accordance with' the retarded velocities of the recoiling parts at each instant of the recoil, whereby the pressure in said cylinder remains substantially constant throughout the recoil, substantially as described.

4. In a gun mount the combination of. a

piston 4and a cylinder provided with a by pass, and means 4comprislng a movable part 'provided with perforations adapted to automatically'control said by ass 1n accordance with the retarded' velocities of the recoiling parts at each instant of recoil, substantially as described.

5. In a gun mount the combination of a recoil cylinder containing a Huid and'provided with a by ass; a iston in said cylin-` der and a cylin rical va ve adapted to control the flow of the said fluid through said by pass in. accordance with the retardbd veloclf.`

ties of the recoiling parts at each instant' of recoil, and thereby causing thevpressure yin the cylinder to remain substantially constant throughout the recoil, substantially.as described. 4 y

6. In a gun mount the combination of a recoil cylinder provided with a by pass: a piston in said cylinder; means to control said by pass in accordance with the retarded velocities of the recoiling parts at each instant ol' recoil; and means to adjust said controlling means in proportion to the elevation oi thc gun, substantially as described.

7. In a gunfnount the combination of a recoil cylinder provided with a by pass; a pis- "ton in said cylinder; a perforated valve adapted to; control said pass in' accordance with the retarded velocities of the recoiling parts at each instant of recoil; and means for automatically adjusting said valve in proportion to any change in the elevation of the gun, substantially as described.

8. In a n mount the combination of a recoil cylin er rovided with a by pass; a piston in said cy nder; a rotary valve provided with openings adapted to control said by pass in accordance with the retarded velocities of the recoiling parts at each instant of recoil; an elevating mechanism and connections ybetween the same and said valve adapted to adjust said valve in proportion to the elevation of the gun, substantially as described.

9. In a gun mount adapted to recoils of different lengths, the combination of a recoil cylinder providedwith a bypass; a piston in said cylinder and a valve provided with plurality of rows of openings, one row for each of said recoils, some of said rows beigng. so arranged and of such an area as to cause a substantially. constant pressure to be main- V tained in said cylinder throughout the length of some of said recoils, and. other rows being adapted to maintain a uniformly decreaslng y pressure in said cylinder throughout the envth of other recoils, substantially as described.

10. In a gun mount adapted to recoils of different lengths, the combination of a recoil cylinder provided with a by pass, and a rotary cylindrical valve controlling said by 4pass and provided with a series of rows of throttling perforations, one for each of said recoils, the combined area ofthe said perforations of some of said rows throttling the said by pass at an instant in certain recoils, being proportionato the retarded velocity of the recoiling parts at that instant, substantially as described.

11. In a different len ths, the combination of a recoil cylinder an with aseries of rows of openings, one for each recoil, and some of said rows adapted to gun mount adapted. to recoils ofa cylindrical valve provided maintain a constant pressure in said cylinder throughout the length offeach of some of said recoils, and other rows adapted to maintain a constantly decreasing -pressure throughout the length of the other recoils, substantially as described.

12. In a. gun mount adapted to recoils of mense lengths,` the combination Vof a -pis-v tb nys recoil cylinder; a. by pass evalve prof' ,vided with a, seriesfof rows of throttling perforations, one for each of saidrecoils, theto tal remainmg area di each row-while throt tling-bein' proportional to the retarded ve-V locity of t e recoilingpa'rts at each instant ofv recoil, said .rows beingsospaeegpart as to revent the said valve from comp etely closssid b pass', 'and means for rotating said' ya. ve w efthe system is atrrest through any desired angle, substantially as described. 13., In 'e gunmount ade `ted to recoils of different len hs, the combination of s recoil cylinder havin s by pass; a cylindrical sliding and rotat1 le .valve't herein having inde pendent rows of perforations for each o f said recolls a iston and piston rod 1n seid valve a. gear w eel on sald piston rod; a second geen* meshing with the saine; a .rod on which rration scribed.

said 'second gear is mounted; aathird gear on said rod; a lourth gear meshing with seid .third geen-ai yshort shaft on which said fourth gear is movgited; s'fth gear on said Shaft; and a curvdrack 'with which said last mentioned gesnieugages, the whole being so elr ranged thnt upon the elevation or depression ofth'e gun, thepsaid valve isv so rotated as to bring that'row of perforations into re .ister withA the saidby pass which' correspon s to the particular .recoil belonging to the ele` question, substantially as de- J. S. GIUSTA, A. W. NEALE, Jr.

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